The Design Of Dual-DSP System And Optimization Of AVS Video Ddecoder

Video has many advantages compared to other media signals such as audio, text, speech, etc. It is more intuitive, concrete, vivid and comprehensive, therefore, the video signal processing theory and technology has always been a research hotspot. In recent years, the application of video&images are more and more widly used, new fields and new markets open up continuously, revealing the huge demand for video applications, particularly in the embedded field. More and more embedded video processing hardware platforms, which have a stronger performance and lower power consumption, are beginning to emerge, effectively promoting the video processing technologies for practical use.Nowadays video information processing technology based on embedded platform has become the most representative and dynamic areas of research and application.The main work of this paper consists of two parts: 1. the design of a dual-DSP-based video processing system; 2. the implementation and optimization of AVS video decoder on TI's Davinci platform. The article first briefly describes the research background of embedded video processing technology, introduces the state of development at home and abroad, and then analyzes some hot embedded video applications, summarizes their common features,and proposes a two-chip processing solution based on ARM + DSP architecture. The chips selected are TI's DM357 and DM6437. DM357 has an ARM core and a video co-processor, responsible for overall system control and video encoding. DM6437 has a C64X+ DSP which dedicated to a variety of video algorithms calculations. Next, the article introduces various modules of the system in detail, mainly including memory modules, video interface, debug module, dual-DSP communication module, the I / O module. Finally, the PCB design of the system is also described briefly. In the software design part, the article first introduces the method of software development on Davinci platform, including Davinci technology, xDAIS / xDM Algorithm Standard, Codec Engine application framework, as well as major steps in Davinci application development. Then a detailed description of AVS decoder's implementation on TI DM6446 platform is given, including program structural adjustment programs, the IALG interface implementation, IDMA3 interface implementation and so on. Upon completion of the AVS codec on DM6446, the further study is their optimization strategy which focus on the cache usage, space allocation and DMA efficiency of the algorithm. After making a number of targeted optimization methods, the decoder's speed increases significantly. The paper gives the testing methods and test results of the decoder. Finally, the article summarizes the hardware&software design work, and proposes a number of directions for improvement.